A winding apparatus having a tension apparatus of a prior art is shown in FIG. 11. A wire-like member 38 which is uncoiled from a supply bobbin 30 is several times wound around a primary tension pulley 31 to which a braking torque is added by a magnetism power mechanism (not shown). An end of the wire-like member 38 is wound around a bobbin 37 through a traversable nozzle 36 and auxiliary pulley 32 and 33. A torque T (kgf cm) which is necessary for rotating the primary tension pulley 31 is expressed by a below formula (1). EQU T=T.sub.1 +J.multidot..omega.' (1)
T.sub.1 : a braking torque (kgf.multidot.cm) PA0 J: an inertia moment of the primary pulley 31 PA0 .omega.': an anglular accelation of the primary pulley 31 PA0 J.multidot..omega.' in the formula (1) is a torque which is necessary for altering a rotating speed of the primary pulley 31 in case of an acceleration in the begining of coiling, and a deceleration in the end of coiling. The tension F (kgf) of the wire-like member 38 is expressed by a below formula (2). EQU F=T/(D/2)=(T.sub.1 +J.multidot..omega.')/(D/2) (2) PA0 D: a diameter of the primary pulley 31
In the formula (2), T.sub.1 /(D/2) is a predetermined tension and J.multidot..omega.'/(D/2) is a change of the tension.
Since the tension of the wire-like member is decided by a friction resistance between the wire-like member 38 and the primary pulley 31, the wire-like member 38 slips on a surface of the primary pulley 31 if the diameter of the primary pulley 31 becomes smaller. Accordingly, the diameter of the primary pulley 31 becomes about 100 mm, when the predetermined tension is imposed on the wire-like member 38 the diameter thereof is about 0.8 mm. After all, the inertia moment J of the primary pulley 31 becomes about 1.times.10.sup.-3 (kg.multidot.cm.multidot.S.sup.2).
In the above-mentioned prior art, since the almost part of the work T.sub.1 .multidot..omega. (kg.multidot.cm/S) which is generated by the braking torque changes the heat in the portion for producing the braking torque, especially the primary pulley 31, the braking torque portion has to be cooled. Accordingly, the primary pulley 31 can not be fast rotated, and the speed for winding wire-like member 38 on the bobbin 37 becomes slow.
Furthermore, the tension apparatus of the prior art needs the shock absorber mechanism, for example the arm 34 which is rotatably fixed on the fulcrum 35, for restraining the change of the tension J.multidot..omega.'/(D/2). As shown in FIG. 11, since the arm 34 is arranged between the primary pulley 31 and the guide nozzle 36, the distance between the primary pulley 31 and the nozzle 36 needs at least 80 cm and the tension apparatus becomes large.